1. Pfizer Inc. (NYSE: PFE) and Medivation, Inc. (Nasdaq: MDVN) announced that they have entered into a definitive merger agreement under which Pfizer will acquire Medivation, a biopharmaceutical company focused on developing and commercializing small molecules for oncology, for $81.50 a share in cash for a total enterprise value of approximately $14 billion.

2. Friday, Rackspace (NYSE: RAX) announced that it entered into a definitive agreement with affiliates of certain funds managed by affiliates of Apollo Global Management, LLC (NYSE: APO), a leading global alternative investment manager, to be acquired for $32.00 per share in cash. In connection with the transaction, funds managed by Searchlight Capital Partners, L.P. will make a strategic equity investment in the acquired company. The transaction has a total value of $4.3 billion, which includes the assumption of $43 million of net cash. Upon completion of the transaction, Rackspace will become a privately held company.

3. Mylan N.V. (Nasdaq: MYL) announced Thursday that it is taking immediate action to further enhance access to EpiPen (epinephrine injection, USP) Auto-Injector by expanding already existing programs in recognition of those patients who are facing the burden of higher out-of-pocket costs. The company is reducing the patient cost of EpiPen Auto-Injector through the use of a savings card which will cover up to $300 for their EpiPen 2-Pak.

4. Real gross domestic product increased at an annual rate of 1.1 percent in the second quarter of 2016, according to the "second" estimate released by the Bureau of Economic Analysis early Friday. In the first quarter, real GDP increased 0.8 percent. Consensus estimates called for a gain of 1.1 percent. The increase in real GDP in the second quarter primarily reflected positive contributions from personal consumption expenditures (PCE) and exports that were partly offset by negative contributions from private inventory investment, residential fixed investment, state and local government spending and nonresidential fixed investment. Imports, which are a subtraction in the calculation of GDP, increased.

5. St. Jude Medical (NYSE: STJ) shares were hit Thursday following a new short report from Muddy Waters. The report suggested that close to half of St. Jude's revenue could disappear for approximately two years as the company's pacemakers, ICDs, and CRTs should be recalled amid cyberattack risk. St. Jude subsequently refuted the allegations on Friday afternoon.

6. Best Buy (NYSE: BBY) rose to a new 52-week high on Tuesday after the big box retailer reported Q2 EPS of $0.57 with revenue of $8.53 billion, compared with consensus estimates calling for EPS of $0.43 on revenue of $8.4 billion. Comps rose 0.8 percent, versus expectations of a 0.5 percent drop. Best Buy also said it was loking for Q317 EPS of $0.43 - $0.47, with the consensus at $0.45.

7. Valeant Pharmaceuticals International, Inc. (NYSE: VRX) announced that Paul S. Herendeen has been appointed Executive Vice President, Finance and will take over the role of Chief Financial Officer from Robert L. Rosiello effective immediately. Mr. Rosiello will remain at Valeant as Executive Vice President, Corporate Development and Strategy. Prior to joining Valeant, he served as Executive Vice President and Chief Financial Officer of Zoetis Inc. (NYSE: ZTS) for two years. From 2005 to 2013 and from 1998 to 2001, Herendeen served as CFO at Warner Chilcott, a specialty pharmaceuticals company.

8. Fed Chairman Janet Yellen spoke at Jackson Hole on Friday. In part, her speech highlighted how the case for another rate hike has gained steam recently. Specifically, the official stated, In light of the continued solid performance of the labor market and our outlook for economic activity and inflation, I believe the case for an increase in the federal funds rate has strengthened in recent months. For the complete speech, click here.

9. CST Brands, Inc. (NYSE: CST) announced that its Board of Directors has unanimously approved a definitive merger agreement with Alimentation Couche-Tard Inc., under which Couche-Tard will acquire all of the shares of CST for $48.53 per share in cash, representing a total enterprise value of approximately $4.4 billion, including the assumption of net debt.

10. Sales of new single-family houses in July 2016 were at a seasonally adjusted annual rate of 654,000, according to estimates released jointly by the U.S. Census Bureau and the Department of Housing and Urban Development this week. The Street consensus called for starts of just 580,000. For more color, click here.